Warp knitting machines



1961 A. w. H. PORTER 2,995,022

WARP KNITTING MACHINES Filed March 9, 1960 4 Sheets-Sheet 1 Aug. 8, 1961A. w. H. PORTER WARP KNITTING MACHINES 4 Sheets-Sheet 4 Filed March 9,1960 I nvenlor Unite Patented Aug. 8, 1961 fine 2,995,022 WARP KNITTINGMACHINES Allan William Henry Porter, Burton-on-Trent, England, assignorto Hobourn-F.N.'F. Limited Filed Mar. 9, 1960, Ser. No. 13,764 Claimspriority, application Great Britain Mar. 26, 1959 9 Claims. (Cl. 66-463)Conventional stop motions which are commonly used in various textilemachines such as warping machines, consist of a row of U-shaped memberseach one of which is individually placed over and supported by a sectionof a single thread which runs substantially horizontally over a pair ofsupports which are spaced apart. If any thread breaks whilst the textilemachine is in operation, its associated dropwire is no longer supportedand falls across a pair of bare electrical conductors arranged below it.The dropwire then completes an electrical circuit through the twoconductors and the closure of this circuit causes the machine to bestopped.

The placing of the individual dropwire in position is a long operationwhich greatly increases the total time necessary to thread up themachine and bring it into operation. Flat warp knitting machines can bethreaded up quite quickly with warp threads which have been fixed inposition side by side by adhesive tape in the usual way. The placing ofindividual dropwire for a stop motion would, therefore, take aparticularly long time in comparison with the remainder of the threadingup. For this reason, stop motions have rarely been used in practice infiat warp knitting machines in spite of their obvious advantage which isthat they enable the machine to be stopped much more quickly andindependently of manual operation when a thread breaks than is possibleif the machine operator must first see the flaw produced by the brokenthread and then stop the machine manually.

According to the present invention a fiat warp knitting machine has astop motion comprising a row of hooked members which are arranged toengage one over each thread and an electrical conductor in an electricalcircuit which on closure stops the machine, the hooked members beingheld spaced apart in guides in which they are movable upwards anddownwards, the hooked members coming into contact with the conductor toclose the circuit on being allowed to move downwards in their guides dueto thread breakage.

When the machine is threaded up, the threads, fixed in groups by theadhesive tape, can readily be passed downwards between the tops of thehooked members and then under the hooks of the hooked members. This ispossible because the hooked members, instead of being entirely separatefrom each other are mounted in guides which maintain their spacing. Inconsequence, the total time taken to thread up a knitting machine havinga stop motion in accordance with the invention is little greater thanthat necessary to thread up a similar machine without a stop motion.

To help maintain the lateral spacing of the threads and to make thethreading up of the stop motion still simpler, a reed may be fixedadjacent and parallel to the row of hooked members and in the path ofthe threads between the warp beam and the hooked members.

There is a tendency for interference between or intermingling ofadjacent threads to cause a hooked member to be held up by an adjacentthread when its associated thread has broken. This tendency is, however,largely overcome by the provision of the reed. The hooked members may,however, be prevented from dropping when their associated threads breaknot only by an adjacent thread, but also by the sticking of adjacenthooked members to each other or to their guides due to oil, suction effcts between flat surfaces in contact with each other or staticelectrical charges built up on the members due to the passage of thethreads through their hooks. To overcome this difliculty according to afurther feature of the invention, a brushing member extends along therow of hooked members. This brushing member has a driving mechanism bywhich it is movable along the row and a series of projecting fingerswhich engage with the shanks of the hooked members as they are movedpast them and impart to the members a slight twisting movement relativeto their guides.

The twisting movements to which the members are continuously subjectedgreatly helps to prevent the members sticking to their guides or to eachother. The projecting fingers may for example be light cantileversprings or may be resilient bristles which may be natural or be made ofnylon.

The brushing member is preferably reciprocated to and fro along the rowof hooked members by a crank or eccentric mechanism so that the hookedmembers are twisted first in one direction and then back again.

An example of a knitting machine constructed in accordance with theinvention is illustrated in the accompanying drawings in which:

FIGURE 1 is a diagrammatic end elevation of the machine;

FIGURE 2 is an end elevation of part of the machine to a larger scaleshowing two stop motions;

FIGURE 3 is a front elevation of one stop motion and the adjacent partsof the machine as seen in the direction of the arrow III in FIGURE 2;

FIGURE 4 is a further end elevation of the machine showing drivingmechanisms for reciprocating brushing members which extend along therows of hooked members of the stop motions;

FIGURE 5 is a front elevation of the machine shown in FIGURE 4, theupper stop motion being shown as seen in the direction of the arrow V inFIGURE 4;

FIGURE 6 is a sectional plan as seen in the direction of the arrows onthe line VIVI in FIGURE 5;

FIGURE 7 is a side elevation of a part of the stop motion;

FIGURE 8 is a front elevation of the part of the stop motion shown inFIGURE 7; and

FIGURE 9 is a detail of one of the hooked members.

The machine is of a conventional type and has at one end a frame 1 andat the other end a similar frame,

which is not shown. A bed, also not illustrated, extends longitudinallybetween the two end frames and carries the knitting elements and theirdriving mechanism. All these parts of the machine are conventional andsince they form no part of the present invention they are notillustrated.

As seen diagrammatically in FIGURE 1 the machine has two warp beams 2and 3 from which warp threads 4 and 5 extend over spring tension bars 6and 7 respectively to a knitting point 8. A stop motion 9 is mountedadjacent the tension bar 6 and a similar stop motion 10 is mountedadjacent the tension bar 7. These stop motions are illustrated in detailin FIGURES 2 to 9 of the draw ings. The two stop motions are generallysimilar to each other and only the stop motion 9 is therefore describedin detail.

The stop motion 9 is fixed by a bracket 11 to an upper member 12 of theframe 1 and the stop motion 10 is fixed by a bracket 13 to a verticalmember 14 of the frame 1. The stop motion 9 comprises a longitudinal bar15 which extends between the bracket 11 and a similar bracket on theother end frame of the machine. Fixed to this bar are a number of diecast metal sections 16, one of which is shown in detail in FIGURES 7 and8 and in each of the sections 16 a number of plates 17 and 18 are castside by side. The plates 17 and 13 form guides between which hookedmembers 19 are freely slidable upwards and downwards. A row of verticalspikes 20 are cast into the top of each of the sections 16 to form areed immediately behind the row of hooked members 19.

A plate 21 is bolted to the bottom of the bar 15 and to this is fixed arail 22 which extends below the bottoms of the row of hooked members 19.The rail 22 forms an electrical conductor and is electrically insulatedfrom the remainder of the structure. The tension bar 6 is supported atintervals on cantilever spring arms 23 from a rod 24 which is in turnsupported at intervals by columns 25 from the bar 15. The rod 24 isclamped in position at each column 25 by a bolt 26 which passes throughthe column 25 and through the bar 15. A keeper rail 27 extends along thelength of the machine above the top of the row of hooked members 19. Thekeeper rail 27 is supported at intervals on arms 28 which are pivoted onthe rod 24. Each arm 28 is normally held in the position shown in FIGURE2 of the drawings by a springloaded catch 29. To enable the machine tobe threaded up the arms 28 can be rotated in a clockwise direction asseen in FIGURE 2 of the drawings so that the keeper rail 27 is raisedinto a position well clear of the top of the reed 20.

Mounted in front of the stems of the hooked members 19 in between theplates 17 and 18 is a brushing member in the form of a bar 30. The bar30 extends along the whole length of the row of hooked members 19 and issupported in a channel-shaped guide 31 in such a way that it can slideto and fro along the row of hooked members 19. The bar 30 is held inposition within the guide 31 by bolts 32 which pass through slots 33 inthe bar 30 and pass through the sections 16 and are screwed into the bar15. Tufts of nylon bristles 34 are held in caps 35 which are removablymounted in bores in the bar 30. When the caps 35 are in position withintheir bores, as shown in FIGURE 2 of the drawings, the bristles 34project through elongated openings 36 in the guide 31 into contact withthe fronts of the shanks of the hooked members 19'.

When the machine is in operation the warp threads 4 pass, as shown mostclearly in FIGURE 2, through the reed 28, through the hooks of thehooked members 19, over the tension bar 6 and thence to the knittingpoint 8. As shown most clearly in FIGURES 7 and 9 the hooked members 19are formed from fiat resilient metal strip, the hooks of the membersbeing crook-shaped. The reverse curved portions 37 of the hooks lie incontact with the shanks of the members. The hooks lie in the plane ofthe row of the shanks of the members.

With this arrangement the stop motion is particularly easy to thread up.The ends of the warp threads 4 are stuck together side by side at aneven spacing by sticky paper in the usual way. The keeper rail 27 israised and groups of threads are passed downwards between the spikes ofthe reed 20 and in between the hooked members 19. The threads passdownwards until they lie below the tips 38 of the hooks and are thenmoved upwards again. As they are moved upwards they pass between theshanks of the hook-shaped members and the reverse curved portions 37 ofthe hooks into the hooks themselves. Because of the springiness of thehooks, the reverse curved portions 37 move back into contact with theshanks and the threads are held in position within their hooks. Thethreads are then drawn over the tension bar 6 and down to the knittingelements in the usual way.

When the machine is in operation the bar 39 is reciprocated to and froby a mechanism shown most clearly in FiGURES 4 to 6 of the drawings.FEGURE 6 is a section through a bar 30' in the stop motion 10, but acorresponding section through the bar 30 is similar.

The driving mechanism comprises a crank 39 which is rotated by aflexible shaft 40 driven by an electric motor 41 mounted on a pedestal42 on the end frame 1. A connecting rod 43 is pivotally mounted on thecrank 39 by a ball bearing 44 and the connecting rod 43 is similarlypivotally attached to the end of the bar 30 by a second ball bearing 45.Thus when the crank 39 is rotated the bar 39 is moved to and fro througha distance equal to twice the throw of the crank 39. As the bar 30 ismoved the tufts of bristles 34 press against the shanks of the hookedmembers 19 and so tend to rock the hooked members to and fro about anaxis extending along their shanks. This continuous brushing against thehooked members prevents their sticking to their guides or to each other.

Normally when the machine is running correctly the hooked members 19 aresubstantially in the position shown in FIGURE 2 of the drawings. As thetension in the warp threads 4 varies the tension bar 6 will move upwardsand downwards and the hooked members 19 will move upwards and downwardsalso. The magnitude of this movement is small, however, so that thebottoms 46 of the hooked members 19 are maintained clear of the rail 22.The hooked members are prevented from being flicked upwards oif thethreads 4 by any sudden upward movement of the tension bar 6 by thekeeper rail 27. If one of the threads 4 should break, its associatedhooked member 19 is no longer supported and moves downwards in its guideformed by the plates 17 and 18 into the position shown in chain dottedlines in FIGURE 7 of the drawings. In this position its bottom end 46comes into contact with the rail 22. This completes an electricalcircuit which passes through the rail 22 and the bar 15 and the sections16 which closes a relay and stops the machine. The electrical circuit ofthe stop motion may be any one of a number of conventional circuitswhich are used with other stop motions and it is not thereforeillustrated.

To facilitate the initial threading up of the machine already described,the tension bar 6, which as seen in FIG- URE 2 is of U-shapecross-section, may be detachably mounted on the ends of the cantileverarms 23 over which it is a push fit. To thread up the reed 20 and thehooked members 19 the tension bar 6 is removed, but after this it isreplaced under the warp threads 4 and pushed back into the positionshown in FIGURE 2 of the drawings.

As already stated the stop motion 10 is generally similar to the stopmotion 9 and corresponding parts are given the same reference numeralsas the parts of the stop motion 9 but with the sufiix a.

I claim:

1. A flat warp knitting machine having a stop motion comprising a row ofhooked members each of which is arranged to engage over and be supportedby one of said threads, a row of guides mounting said hooked members inside by side spaced apart relation for up and down movement, a brushingmember extending along said row of hooked members, a driving mechanismformoving said brushing member along said row, a series of fingersprojecting from said brushing member and engaging with said hookedmembers as said brushing member moves to impart a slight twistingmovement to said hooked members relative to said guides to maintainfreedom of up and down movement of said hooked members in said guides,an electrical conductor below said hooked members positioned to becontacted by one of said hook members whenever that hook member ispermitted to fall consequent upon breakage of the thread supporting it,an electrical circuit passing through said conductor and closed bycontact between said conductor and a hook member, and means actuated byclosing of said circuit for stopping said machine.

2. A machine according to claim 1, in which the driving mechanismreciprocates the brushing member to and fro along the row of hookedmembers.

3. A machine according to claim 1, in which the fingers are bristles.

4. A machine according to claim 3, in which the bristles are mounted intufts in caps which are removably fixed to the brushing member.

5. A machine according to claim 1, in which the hooked members areresilient sheets of metal formed into shanks and crook-shaped hooks,said hooks comprising reverse curved portions adjacent their tips whichare in contact with said shanks.

6. A machine according to claim 5, in which the hooks of the hookedmembers lie in the plane of the row of shanks of said hooked members.

7. A machine according to claim 1, in which a keeper rail is providedabove the tops of the hooks of the row or hooked members.

8. A machine according to claim 7, in which the rail is mounted onpivoted arms which allow the rail to be swung upwards clear of thehooked members for thread- 6 ing up to take place, the arms havingspring detents which hold them in the upper and lower positions.

9. A machine as claimed in claim 1 which carries a pair of springcantilever arms, each formed with an upwardly projecting spigot, and atension bar which fits detachably over said spigots to tension saidthreads.

References Cited in the tile of this patent UNITED STATES PATENTS871,724 Moran Nov. 19, 1907 1,777,503 Remington Oct. 7, 1930 2,323 ,282Kaufmann June 29, 1943 2,447,553 Barnes et a1 Aug. 24, 1948 2,700,880Home Feb. 1, 1955 2,734,362 Schiek Feb. 14, 1956

